This book constitutes the refereed proceedings of the 16th Internation al Conference on Automated Deduction, CADE-16, held in Trento, Italy i n July 1999 as part of FLoC'99. The 21 revised full papers presented w ere carefully reviewed and selected from a total of 83 submissions. Al so included are 15 system descriptions and two invited full papers. Th e book addresses all current issues in automated deduction and theorem proving, ranging from logical foundations to deduction systems design and evaluation.